lib/libutil/login_auth.c

   1 /*-
   2  * Copyright (c) 1996 by
   3  * Sean Eric Fagan <sef@kithrup.com>
   4  * David Nugent <davidn@blaze.net.au>
   5  * All rights reserved.
   6  *
   7  * Portions copyright (c) 1995,1997 by
   8  * Berkeley Software Design, Inc.
   9  * All rights reserved.
  10  *
  11  * Redistribution and use in source and binary forms, with or without
  12  * modification, is permitted provided that the following conditions
  13  * are met:
  14  * 1. Redistributions of source code must retain the above copyright
  15  *    notice immediately at the beginning of the file, without modification,
  16  *    this list of conditions, and the following disclaimer.
  17  * 2. Redistributions in binary form must reproduce the above copyright
  18  *    notice, this list of conditions and the following disclaimer in the
  19  *    documentation and/or other materials provided with the distribution.
  20  * 3. This work was done expressly for inclusion into FreeBSD.  Other use
  21  *    is permitted provided this notation is included.
  22  * 4. Absolutely no warranty of function or purpose is made by the authors.
  23  * 5. Modifications may be freely made to this file providing the above
  24  *    conditions are met.
  25  *
  26  * Low-level routines relating to the user capabilities database
  27  *
  28  * $FreeBSD: src/lib/libutil/login_auth.c,v 1.11 1999/08/28 00:05:45 peter Exp $
  29  * $DragonFly: src/lib/libutil/login_auth.c,v 1.3 2005/03/04 04:31:11 cpressey Exp $
  30  */
  31
  32 #include <sys/types.h>
  33
  34 #include <fcntl.h>
  35 #include <paths.h>
  36 #include <stdio.h>
  37 #include <stdlib.h>
  38 #include <unistd.h>
  39
  40 #include "login_cap.h"
  41
  42
  43 /*
  44  * auth_checknologin()
  45  * Checks for the existance of a nologin file in the login_cap
  46  * capability <lc>.  If there isn't one specified, then it checks
  47  * to see if this class should just ignore nologin files.  Lastly,
  48  * it tries to print out the default nologin file, and, if such
  49  * exists, it exits.
  50  */
  51
  52 void
  53 auth_checknologin(login_cap_t *lc)
  54 {
  55   char *file;
  56
  57   /* Do we ignore a nologin file? */
  58   if (login_getcapbool(lc, "ignorenologin", 0))
  59     return;
  60
  61   /* Note that <file> will be "" if there is no nologin capability */
  62   if ((file = login_getcapstr(lc, "nologin", "", NULL)) == NULL)
  63     exit(1);
  64
  65   /*
  66    * *file is true IFF there was a "nologin" capability
  67    * Note that auth_cat() returns 1 only if the specified
  68    * file exists, and is readable.  E.g., /.nologin exists.
  69    */
  70   if ((*file && auth_cat(file)) || auth_cat(_PATH_NOLOGIN))
  71     exit(1);
  72 }
  73
  74
  75 /*
  76  * auth_cat()
  77  * Checks for the readability of <file>; if it can be opened for
  78  * reading, it prints it out to stdout, and then exits.  Otherwise,
  79  * it returns 0 (meaning no nologin file).
  80  */
  81
  82 int
  83 auth_cat(const char *file)
  84 {
  85   int fd, count;
  86   char buf[BUFSIZ];
  87
  88   if ((fd = open(file, O_RDONLY)) < 0)
  89     return 0;
  90   while ((count = read(fd, buf, sizeof(buf))) > 0)
  91     (void)write(fileno(stdout), buf, count);
  92   close(fd);
  93   sleep(5);     /* wait an arbitrary time to drain */
  94   return 1;
  95 }